5 Things to Know Before Buying Concrete Reinforcing Rebar Support Chairs

I have recently received information from an associate whom has just returned from the ConExpo. During the Expo he was approached by several people enquiring as to the extruded plastic rebar support ( bar chairs ) he was he using in an exhibit. He was queried as to where he obtained these plastic rebar support ( bar chairs )as they had not seen anything similar in the States. If this is the case what method is employed to hold the rebar in position. G'day Boffintech

Within Australia plastic bar chairs are used extensively in suspended slabs, beams and columns. I have never experienced any failure of the plastic bar chairs, nor have I ever heard of a failure. The plastic bar chairs are more than capable of supporting both materials and men.

Can you direct me to a supplier or manufacturer of plastic rebar chairs within the States as I'm interested as to the differences between the chairs as used within each country.

Thanks for the information. Never heard of a broken plastic rebar support chair? Amazing.

All I can tell you is that I inspect suspended slabs daily, and as a result I see broken plastic rebar support chairs daily. I'll take some digitals and see if I can post them. The worst ones are the ones over 6 1/2" because they are made up of two chairs zip-tied together. Any kind of twisting or lateral loading and they just pop apart of fold up. G'day boffintech

Thanks for the information.

The problems I have encountered with the plastic tipped metal bar chairs is the tendency to tip over due to the small footprint plus they are only designed to carry one bar. The plastic chairs are combinations where both top & bottom steel of the mat can be carried with a single chair.

Metal tipped bar chairs are available and utilized by some people given the size of bar chairs range from 20 mm to 360 mm high. The metal chairs are commonly used during slab on ground construction

By Joe Kirkwood and Holly Kirkwood

For more information, please visit Trico.

Rebar or bar support is a term used to describe products that elevate rebar in reinforced concrete. When concrete is poured for bridges, roads, runways, foundations, caissons, etc., rebar and bar supports are required to strengthen the structure and to provide additional support. Rebar is needed to when pouring big slabs of concrete to reinforce the strength of the concrete and to help reduce cracking. Rebar aids in absorbing and distributing tension caused when concrete expands and contracts due to climate variations (hunker.com). In order to have rebar in a concrete pour, contractors also need rebar support. The type of rebar or mesh support used depends on the type of surface underneath the concrete, the structural elements and the design of the project.

There are several types of rebar support used depending on the needs of the project. The CRSI (Concrete Reinforcing Steel Institute) has implemented standards for such products. At Outpost, we have found Dayton Superior to be our company of choice when it comes to complying with these standards. And of course, they get bonus points for being the industry standard of products Made in America. Below we break down the different types and styles of rebar or bar support and their uses.

CS - CONTINUOUS SUPPORT (aka Zig-Zags)

Continuous support is a continuous, vertical steel spacer for thick and heavy concrete applications. The support provided is stable and because of its weight, will not slide or tip. Zig Zags typically sit in the middle of the concrete. Because of its design, it can be bent around partitions and continue to hold its load-bearing capacity.

Specs:
• Height covers 2” to 16”
• Available in plain black or epoxy coating (prevents rust)
• Uses: In deep and thick concrete pours such as highways, runways, and taxiways

Castle Chair

Castle Chairs are used to maintain the elevation of rebar in reinforced concrete. The chair is cone shaped with rebar saddles and a wide base. The wide base prevents it from sinking into the dirt or base below it. The rebar intersections where the rebar ties together are what sit on top or in the rebar saddles. Castle Chairs keep the rebar off sub-straight and in its specified, engineered position.

Specs:
• Cover height 1-1/2” to 6-1/4” in ¼” increments (Dayton Superior)
• Plastic footing to keep from corroding
• Available in epoxy coated or plain
• Uses: Any concrete pour, interior slabs, driveways, etc.

SNAP-ON MESH CHAIR

Snap-On Mesh Chairs are used for high heat resistance and high strength applications and are mostly used with mesh sheets as opposed to rebar. They can support 8’ x 20’ sheets or smaller on grade at heights from 1” to 6.” The small clip on top provides a “lock-in” stability to the wire and the large base provides excellent stability.

Specs:
• Covers 1” to 6” height
• Uses: Concrete slabs or driveways, for bigger spaces, anything over 8’ wide (if you’re not using rebar)

SLAB BOLSTER UPPER (aka BEAN BOLSTER)

Slab Bolster also known as continuous bar chair support, are used to support one layer of steel above another. The base is made of two even, continuous bars brought together by one top support bar connected by even spaced legs. The continuous bar support covers more distance with more support by placing multiple supports together.

Contact us to discuss your requirements of Concrete Reinforcing Rebar Support Chairs. Our experienced sales team can help you identify the options that best suit your needs.

Specs:
• Cover height ¾” to 5” in ¼” increments (Dayton Superior)
• Available in plain or epoxy coated
• Uses: Engineer specific, but normally used for bridges, highways, bigger projects

BEAM BOLSTERS

Beam Bolsters have a similar design as slab bolsters but do not have the continuous bar base. Instead, the top bar is supported by evenly spaced legs. The uses are similar to slab bolster but depend on the engineer and design of the project.

Specs:
• Cover height 1” through 5” in ¼” increments (Dayton Superior)
• Legs spacing 2 ½” centers
• Available in epoxy and steel
• Uses: Engineer specific, but normally used for bridges, highways, bigger projects

BAR CHAIR

Bar chairs are typically used for wide spaced, light steel in slab/deck construction. The bar chairs are lightweight and easy to install providing stability with their 4-point contact base. The foot is designed to set on most forming surfaces (Dayton Superior).

Specs:
• Cover height ¾” to 2,” ¼” increments
• Available in epoxy, plain, plastic tipped, plastic dipped and galvanized

CONTINUOUS MESH SUPPORT

Continuous mesh support is made up of two runner wires at the base one top supporting wire connected by evenly spaced legs in between. It’s used to support one layer of steel above another.

Specs:
• Cover height ¾” to 10” in ¼” increments
• Strong, resistance welded construction that withstands job site compressive loads without deforming, faster fulfillment times
• Available in plain, epoxy, or galvanize
• Uses: support steel on the soft material form surface

CONTINUOUS HIGH CHAIR UPPER

The continuous high chair upper is very similar to the continuous mesh support. These supports are available in carbon steel, stainless steel, and chromium steel, differentiating them from the mesh support as a sturdier option.

Specs:
• Cover height to 2” to 30” in ¼” increments
• Available in plain, epoxy, or galvanized
• Uses: Support steel or soft material form surfaces

There are many options when it comes to choosing a rebar support for your concrete pour. We suggest consulting your Outpost rep to find the best option for your jobsite!

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